Outlook 365 on Windows 10: being prompted to login with username always preceded by "MicrosoftAccount\"

Bruce Patterson 101 Reputation points
2020-10-09T14:05:43.967+00:00

Morning!

Outlook is prompting me to login with my 365 username preceded by "MicrosoftAccount\". Entering the pw, with or without this, fails. Reset Outlook OST settings back to new, no change. Removed anything related to Office in Credentials Manager, restarted, no difference. Meanwhile on my second computer, using the exact same setup/config, no issues.

So... how can I reset/uninstall Outlook 365 without impacting any other 365 app, all of which seem to be working fine otherwise, ie Onedrive, Excel, etc?

If the only option is remove Office 365 entirely, what's the best way to do that to clobber this sudden credential challenge?

Thanks.

Outlook Management
Outlook Management
Outlook: A family of Microsoft email and calendar products.Management: The act or process of organizing, handling, directing or controlling something.
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  1. Bruce Patterson 101 Reputation points
    2020-10-20T18:29:27.957+00:00

    Hi Jeff, I thought about this more over the weekend, and today connected with my client and turned their Microsoft 2fa off, and voila!

    Just to be safe, I cleared the local profile Outlook folder, and launched Outlook. I was prompted with the "MicrosoftAccount..." credential request as before, so I entered the 365 pw - this time it confirmed the response, and began downloading the requisite profile and OST!

    Whew, but uncertain of why the 2fa was foiling this necessary authentication on one PC, while the same profile was working fine all along on the second PC. I confirmed that it now being disabled had no other effect on the second PC, or that I wouldn't be prompted again with the "MicrosoftAccount..." credential request again - I did this by restarting Outlook several times, without issue.

    So, the culprit is Microsoft 2fa? A very desirable security feature, for sure, but now I'm nervous to reenable without understanding what happened here. And I definitely think the Troubleshooter tools need to take 2fa issues into account, or to at least suggest a temp disable as a troubleshooting step?

    Thanks.

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  1. JeffYang-MSFT 6,241 Reputation points Microsoft Vendor
    2020-10-12T05:55:53.687+00:00

    Renew:

    Hi @Bruce Patterson ,
    As I know, we could not separately uninstall Outlook from the "Click to run" subscription of Office 365.

    What's the version of your Outlook 365? (File > Office Account > About Outlook). Since you have mentioned that the same email account could work fine on your second computer, it is suggested for you to compare the Outlook version between this problematic Outlook client and the normal Outlook client. If their Outlook version is indeed different, please try to upgrade the problematic Outlook to the same version as the normal one and see if the issue could be resolved.

    Besides, have you already tried the rename Outlook1 method I mention before? If not, you could try it and see how will this issue go. If it still not works, considering you have tried some workarounds such as Credentials Manager before, and I'm afraid that the remaining workarounds that we can can try might be limited.

    1. Exit Outlook and open the Registry Editor
    2. Navigate to: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0
    3. Right-click the "Outlook" folder
    4. Rename it as "Outlook1"
    5. Open your Control Panel, View by Small icons and open "Mail(Microsoft Outlook 2016)"
    6. Click "Add" to add a new Outlook profile and re-configure your email account
    7. Restart your Outlook and check

    Using two-step verification with your Microsoft account might could be able to help Outlook skip "MicrosoftAccount\" prompt. If possible, it is suggested to turn on the two-step verification feature with your account and you could learn more about that in this article: How to use two-step verification with your Microsoft account. Or, we might need to perform a clean installation of Office to completely solve this problem just as you mentioned.

    If the only option is remove Office 365 entirely, what's the best way to do that to clobber this sudden credential challenge?

    I'm afraid it's hard to define what cause is mainly related to this issue right now. Usually, factors like windows Credential Manager and Outlook settings might indeed cause issues like this. I searched a lot about that, here is some other similar thread for you to reference:
    Outlook asking about MicrosoftAccount credentials
    Outlook Prompts for Personal Microsoft Account Instead of Office 365 Account
    Fix Microsoft Outlook Repeatedly Keeps Asking for a Password
    (Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.)

    Hope these can be useful.

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